Tag Archives: lunar module

[March 16, 1969] Flight of the Space Spider (Apollo 9)



by Kaye Dee

Riding on Apollo's Coat-tails
The Traveller recently referred to President Nixon’s 8-day European tour, but it would seem Mr. Nixon deliberately decided to pave the way by riding on the coat-tails of the general international applause accorded to the historic Apollo-8 mission. Shortly before he announced his own trip to Europe, the President personally dispatched Apollo-8 commander Colonel Frank Borman and his family on an eight-nation European goodwill tour. (The other Apollo-8 crewmembers, already in training as part of the Apollo-11 backup crew, were not available to participate in the tour.)


Departing on 2 February, Col. Borman, his wife Susan, and two sons undertook a 19-day tour, visiting the UK, France, Belgium, the Netherlands, West Germany (including West Berlin), Italy (including Vatican City), and Spain (like Australia, home to an Apollo Manned Space Flight Network station and a Deep Space Network facility): an itinerary very closely paralleling that later followed by President Nixon!

The Borman family meets the Royal Family and Col. Borman presents a picture of the Moon to the Pope during his goodwill tour of Europe

Col. Borman said that he was particularly gratified to make the journey because of a conviction that space efforts “can be a very positive force for creating better relations among the people of the world”.

A Long-Delayed Mission
But while Colonel Borman was embarking on his diplomatic mission, the crew of the long-delayed first test flight of the Lunar Module (LM) in Earth orbit were in the final stages of preparations for the Apollo-9 mission, which splashed down just a few days ago with all its objectives successfully completed. Intended to be Apollo-8, the mission was bumped later in the sequence due to a succession of technical delays in the development of the LM, the first manned spacecraft designed solely for operations in space.


Apollo-9’s main task was to qualify the LM for manned lunar flight, demonstrating that the craft could perform all the necessary manoeuvres required for a landing on the Moon. The flight was therefore intended to be very much a mission of “firsts” that would finally fully test-out the entire suite of hardware needed to accomplish a Moon landing mission. It would see the first flight of the complete Apollo Saturn vehicle – Saturn V launcher (AS-504 for this mission), Command Service Module (CSM-104) and Lunar Module (LM-3) – as well as the first docking and extraction of a LM from the Saturn S-IVB stage.


 
Putting the LM through its paces would involve the first flight tests of its upper and lower stages, with the first firings of their engines in space, and include the first rendezvous and docking between with the CSM and LM. The mission would also undertake the first spacewalk of the Apollo programme, to test the reliability of the Apollo A-7L space suit and the Portable Life Support System (PLSS) backpack, essential for lunar surface operations.

The Crew Who Waited
Original 1966 crew photo of Astronauts Scott, McDivitt and Schweickart. Their training for the flight that eventually became Apollo-9 commenced in January 1967, even before the Apollo-1 fire

Probably the best prepared mission crew to date, the Apollo-9 crew originally came together in January 1966, as the back-ups for Apollo-1, before being assigned as the first crew to fly the LM. Their 1,800 hours of mission-specific training was equivalent to about seven hours for every hour of their eventual flight!

With so much riding on a successful LM test flight, Apollo-9’s crew comprised two veteran Gemini astronauts and one rookie. Mission Commander Air Force Col. James McDivitt previously commanded the Gemini-IV mission, during which the first US EVA was conducted. Command Module Pilot Lt.-Col. David Scott, also with the US Air Force, was Pilot of Gemini-VIII, its flight cut short by the first US in-flight space emergency, but for which he undertook considerable EVA training.

Finally Go for launch! Astronauts McDivitt, Scott and Schweickart in their official Apollo-9 pre-flight crew portrait

The new kid on the block for Apollo-9 was LM Pilot Mr. Russell Schweickart, originally selected in the third group of astronauts in 1963. An experienced fighter pilot, serving with the U.S. Air Force and the Massachusetts Air National Guard between 1956 and 1963, Mr. Schweickart joined NASA as a civilian, from a position as a research scientist at the Experimental Astronomy Laboratory of the Massachusetts Institute of Technology (MIT). Mr. Schweickart is nicknamed “Rusty” for his red hair (but in Australia, with our sense of humour, we’d have called him “Bluey”!).

Introducing Gumdrop and Spider
Because Apollo-9 would have two spacecraft from the same mission operating independently for the first time (unlike the Gemini VI-VII rendezvous, in which the two spacecraft were separate missions with their own callsigns), they each required separate callsigns for easy communications identification. NASA Administrators therefore finally lifted the ban on spacecraft names, which has been in operation since the beginning of the Gemini programme, permitting the crew to select their own names for the CM and LM.

The Apollo-9 CSM and LM being prepared for launch at Kennedy Space Centre

The astronauts chose “Gumdrop” for the CM, based on the shape of the capsule, which resembles the popular sweet, and “Spider” for the LM, given the spider-like appearance of the lander, with its four spindly legs. Unfortunately, it seems that certain NASA officials were not happy with these choices, feeling they were not dignified enough, so I hope they will not place restrictions on the names that can be selected for future missions, or force the crews to revert to dull numerical callsigns.

Patching Up
North American Rockwell artist Allen Stevens seems to be quite a favourite with the Apollo astronauts as a mission patch designer. He has designed the patches for Apollo-1, 7 and Apollo-9, and seems to have had a strong influence on the design of the Apollo-8 patch.

Stevens’ Apollo-9 patch evolved from a design he originally developed when Apollo-9 was still anticipated to be Apollo-8. The relatively simple concept depicts all the vehicle elements of the Apollo mission – the Saturn V in launch configuration, with the CSM and the LM flying separately as they would do during orbital test manoeuvres. In the final version of the design they appear against a mottled blue background that could represent either the Earth’s oceans or orbital space. Rather than show the CSM and LM docked together in orbit, as we often see them in NASA illustrations, Stevens chose to depict them in their on orbit ‘station-keeping’ positions, with the CSAM and LM facing each other, although this does give the impression that the CM is attempting to dock with the front of the LM!

Completing the design, the names of the crew and mission circle just inside the red-bordered edge of the patch, with the “D” in McDivitt’s name also filled in red. This is a nod to Apollo-9 being originally designated as the “D” mission in the sequence of Apollo flights prior to the Moon landing.

A Busy Moonport
Due to the long delay with the LM, preparations for Apollo-9 initially overlapped those of Apollo-7 and 8. By February, while the astronauts were spending long hours in mission simulators preparing for their flight, Kennedy Space Centre (KSC) was a hive of activity with Apollo-9 in the final stages of pre-launch testing, and advance preparations for Apollo 10 and Apollo 11 also underway (Apollo 10 is currently due for launch in May and Apollo 11 in July).  

In addition to Apollo-9’s launch preparations, the Apollo 10 spacecraft was moved from the Manned Spacecraft Operations Building (MSOB) to the Vehicle Assembly Building (VAB) for mating with its Saturn V launcher (above left); the first and second stages for the Apollo 11 Saturn V arrived, with the stacking of that launcher commencing in the VAB (above right); and the upper and lower stages of the Apollo 11 LM were also mated in the MSOB, in preparation for testing in the altitude chamber. NASA is really moving at a cracking pace to achieve a manned lunar landing this year!

An Unexpected Delay
The countdown for Apollo-9 commenced on 26 February, for a planned launch on the 28th. But fate stepped in to delay the crew’s trip to space just a bit longer! Ironically, despite their years of training for this mission, the astronauts pushed themselves so hard in their final weeks that, as launch day approached, they developed cold-like symptoms such as sore throats and nasal congestion.

Apollo-9's LM crew, McDivitt and Schweickart, training in the Lunar Module simualator

For NASA’s most complex manned mission to date, senior managers and flight surgeons wanted the crew to be in the best possible health for the 10-day flight. (They were probably also mindful of preventing a recurrence of the issues with the Apollo-7 crew, due to in-flight health problems). Consequently, the launch was rescheduled to 3 March to give the astronauts time to recover.

Finally on their Way!

 

 

 

 

 

 

 

 

 

 

 

 

 

Once KSC medical director Dr Charles Berry finally cleared the crew for launch, Apollo-9 left the pad exactly on time at 16:00GMT on 3 March. Hopefully the smooth launch impressed Vice President Spiro Agnew (on right in the picture below), who was present in the Launch Control Centre in his new role as Head of the National Space Council, especially as President Nixon has asked his science adviser, Dr Lee Dubridge, to report on possible cost reductions within the US space programme.

To maximize the chances of accomplishing them, in case any problems forced an early return to Earth, the most critical mission tasks were scheduled for the first five days of the flight. So once the Saturn rocket’s S-IVB third stage and the CSM were safely in orbit, things moved quickly. During the second orbit, CM Pilot Scott turned the CSM and successfully docked with the Lunar Module, nestled in the Spacecraft-Lunar Module Adapter of the S-IVB stage. The linked spacecraft were ejected from the S-IVB, which was then remotely controlled to simulate Trans-Lunar Injection and eventually be sent into a solar orbit.

Demonstrating that the “probe and drogue” CM-LM docking assembly worked properly is another crucial step towards enabling the future Moon landing. If this system didn’t work, a lunar landing would not be possible.

Once the probe is inserted in the drogue it retracts and pulls the two spacecraft together so that a series of twelve latches locks them tight.

Burning Along
Six hours into the mission, the next task was to establish that the docked CSM-LM could be manoeuvred using the Service Module’s Service Propulsion System (SPS) engine. A five-second burn placed the CSM in an orbit of 125 by 145 miles, to improve its orbital lifetime. This short firing demonstrated the CSM guidance and navigation system’s ability to control the burn and showed that the LM’s relatively light structure could withstand thrust, acceleration and vibration.

Following the first sleep period on an Apollo mission during which all three astronauts slept at the same time, Apollo-9’s second day focussed on putting the SPS engine, and the CSM, to the test, through a series of three burns. The first burn, lasting 110 seconds, raised Apollo 9’s orbit to 213 miles and tested the structural dynamics of the docked spacecraft under conditions simulating a lunar mission. This involved gimballing (swivelling) the SPS engine to determine whether the spacecraft’s guidance and navigation autopilot could dampen the induced oscillations. The CSM remained very stable, with the oscillations damped within just five seconds.

Apollo spacecraft diagram key. CSM (right) and LM (launch configuration) docked. I – Lunar module descent stage; II – Lunar module ascent stage; III – Command module; IV – Service module. 1 LM descent engine skirt; 2 LM landing gear; 3 LM ladder; 4 Egress platform ("porch"); 5 Forward hatch; 6 LM reaction control system quad; 7 S-band inflight antenna (2); 8 Rendezvous radar antenna; 9 S-band steerable antenna; 10 Command Module crew compartment; 11 Electrical power system radiators; 12 SM reaction control system quad; 13 Environmental control system radiator; 14 S-band steerable antenna

The second SPS burn lasted 280 seconds, changing the orbit to 126 by 313 miles, while the short third burn, just 28.2 seconds, changed the plane of the spacecraft’s orbit. These orbital changes were designed to position Apollo-9 for better ground tracking and lighting conditions during upcoming mission activities.

Space Sickness Strikes
Entering the LM and checking out its systems was scheduled for flight day three, but planned operations were initially disrupted when space sickness reared its head. Flight surgeons still know little about this condition, which seems to affect some astronauts but not others, and some more than others.

A view inside Command Module Gumdrop

Both Col. McDivitt and Mr. Schweickart were affected, with McDivitt apparently experiencing some mild nausea. Mr. Schweickart, however, vomited in the CM and again later in the LM. When Col. McDivitt contacted the flight surgeons from the LM to report the medical situation, they were less than happy that the earlier incident had not been initially reported, as they could have treated Schweickart’s symptoms sooner.

Opening Up the LM
Although the initial bout of space sickness delayed the start of operations to clear the docking tunnel and access the LM, the astronauts were able to continue with the day’s activities, and both Commander and LM Pilot used the docking tunnel to make the first ever transfer between manned spacecraft without needing to spacewalk. With Lt.-Col. Scott remaining in the CM, and hatches between the Gumdrop and Spider closed, the LM’s communications and life support systems demonstrated that they were operating independently from the CM. Schweickart also deployed Spider’s landing legs (which had been folded for launch) into the position they would assume for landing on the Moon, giving the LM the appearance of its namesake!


A Jumping Spider!
During the nine hours they inhabited Spider, still docked to the CSM, Col. McDivitt and Mr. Schweickart conducted a major test of the Lunar Module’s descent engine, firing it for 367 seconds to simulate the pattern of throttling planned for a descent to the lunar surface. For the final 59 seconds of the burn McDivitt controlled the throttling, varying the thrust from 10 to 40 percent and shutting it off manually, marking the first manual throttling of an engine in space.

This burn, which demonstrated that the LM descent engine could manoeuvre the combined LM-CSM stack, was followed by an additional SPS firing after the LM crew returned to the CM. Together, these burns placed Apollo 9 into an orbit of 142 by 149 miles, ahead of the rendezvous exercises to be performed on day five.

Red Rover (Doesn’t Quite) Cross Over
The step-by-step testing program for Apollo-9 earmarked the fourth day of the mission for a spacewalk to test the reliability of the Apollo EVA suit and the PLSS backpack, necessary because it would be impractical and dangerous for astronauts to move across the Moon’s surface trailing umbilical lines connected to the LM. As the only EVA scheduled before the Moon landing, it was the single opportunity to test the PLSS operationally in space.

Astronaut Schweickart training for his planned EVA

Using the call sign “Red Rover”, “Rusty” Schweickart was originally scheduled to perform a two-hour EVA to simulate a space rescue technique in the event that a CM-LM docking could not be made, crossing from Spider to Gumdrop. This would have involved him exiting the hatch on the LM and making his way along the outside of the spacecraft to the CM hatch, where Lt.-Col. Scott would be standing by to assist access to the CM. However, the LM Pilot’s bout of space sickness led Col. McDivitt to initially cancel the EVA, due to the flight surgeons’ concerns about the dangers of vomiting in a spacesuit. This also meant the cancellation of a planned TV broadcast of the spacewalk itself, which would have been another first.

Wearing Golden Slippers
But with Mr. Schweickart feeling somewhat better by day four, a modified short EVA was substituted to enable the EVA equipment test to be carried out. After McDivitt and Schweickart again transferred to Spider, Mr. Schweickert climbed out onto the LM porch for a 37.5-minute EVA, exclaiming “Hey, this is like spectacular” as he stood in the void. For much of this time, the astronaut’s feet were held in gold-coloured restraints, nicknamed the “Golden Slippers”, but he was also able to move around the LM’s exterior using handholds to retrieve some experiments.

At the same time, David Scott, wearing a bright red helmet, made a stand-up EVA in Gumdrop’s hatch and both astronauts photographed each. Scott, too, retrieved experiments from outside the CM. Mr. Schweickart has said that he found moving around easier than it had been in simulations and was confident that he could have completed the spacewalk to the CM had it gone ahead.

The Spider Takes Flight

The key event in Apollo -9’s programme was the undocking and rendezvous tests scheduled for the fifth day of the mission. These manoeuvres would simulate all the activities required for a successful lunar landing and return to lunar orbit. With McDivitt and Schweickart in Spider, and Scott remaining in Gumdrop, the two craft undocked to commence a complex set of manoeuvres and burns of both the LM descent and ascent engines. These tests also carried a new element of danger. The Lunar Module has no ability to return to Earth on its own, since it lacks a heatshield: if something went seriously wrong its crew could end up stranded in space with no way home.

After 45 minutes separated but station keeping, an initial 24.9-second LM descent engine burn placed Spider into a 137 by 167 mile orbit; a second 24.4-second firing circularized the orbit around 154 by 160 miles, approximately 12 miles higher than Gumdrop. Over the next four hours, McDivitt fired the LM’s descent engine at several throttle settings, before lowering Spider’s orbit to begin a two-hour ‘chase’ to catch-up with Gumdrop. The LM descent stage was then jettisoned, and the ascent stage engine fired for the first time, lowering the LM’s orbit still further and placing Spider 75 miles behind and 10 miles below Gumdrop for the rendezvous manoeuvre.

Although it is planned that in future Moon missions, the Command Module pilot will conduct the rendezvous with a returning LM, for Apollo-9 Spider carried out the rendezvous, to demonstrate that the manoeuvre could be performed by either craft. Apart from this difference, the approach and rendezvous hewed as closely as possible to the current plans for lunar missions. Mission Commander McDivitt flew the LM close to Gumdrop, manoeuvring Spider so that CM Pilot Scott could see each side of the vehicle and inspect it for any damage. As he photographed the ascent stage, Scott joked “You’re the biggest, friendliest, funniest looking Spider I’ve ever seen.”

McDivitt then docked to the CM, guided by Scott, as Sun glare was interfering with his vision. Once Spider’s crew returned to Gumdrop, the ascent stage was jettisoned and remotely commanded to fire its engine to fuel depletion, simulating an ascent stage’s climb from the lunar surface. With the approach and rendezvous operation complete, the only major LM system that had not been fully tested during Apollo-9 was the lunar landing radar.

A Bit Camera Shy
Unlike the previous two missions, Apollo 9’s packed programme restricted the television broadcasts made by the astronauts. Spider was equipped with a Westinghouse b/w Lunar Surface Lunar TV Camera, identical to the one taken to be carried to the Moon’s surface on the first landing, as another equipment trial. This low-light “slow scan” camera produced a 320 line, 10 frames per second non-interlaced picture.

Only two broadcasts were from Spider. The first, seven minutes’ long, occurred on day three and showed Mr. Schweickart and Col. McDivitt working in the confined space of the LM. The second broadcast occurred shortly after the end of the EVA on the fourth day, with Spider’s crew still wearing their spacesuits.

The quality of this 15-minute transmission was much better than the previous day, and the crew treated viewers to a scene of Col. McDivitt eating. The camera was then pointed out the LM’s top window to show Gumdrop, then through one of the forward windows to glimpse one of Spider’s attitude control thruster quads and a landing leg. Finally, the view switched back into the cabin to show the LM’s instrument panel and a radiation detector. Once the LM ascent stage was jettisoned, on day five, there were no further broadcasts as the CM did not carry a television camera.

Cruisin' in Orbit
Once the crowded test schedule of the first five days was complete, the second five days of Apollo-9’s flight, intended to test the endurance of the CSM for the total length of a Moon landing mission, were quiet and relaxed by comparison.

Col. McDivitt thanked the Mission Control team for their work during the hectic first half of the mission and jokingly mused: “Might give you the impression that it might work, huh?” The crew sang a belated “Happy Birthdays” to Christopher C. Kraft, Jr., Director of Flight Operations at the Manned Spacecraft Centre, and Apollo 9 crew secretary Charlotte Maltese.

There were additional SPS burns on days six and eight to change the spacecraft’s orbit, with no major activities scheduled for the ninth day, although the astronauts made observations of the Pegasus 3 satellite, passing within 1,000 miles and 700 miles of Apollo 9 during two successive orbits. They also observed the LM ascent stage from about 700 miles away.

Observing the Earth
The main activity of the second half of the Apollo-9’s flight was the mission’s only formal scientific investigation, a programme of multi-spectral terrain photography, using four Hasselblad 70 mm cameras pointed out the CM’s round hatch window. This allowed photographs to be taken in four specific wavelengths of the visible and near infrared spectrum simultaneously.

Multi-spectral images. The same view of San Diego and parts of California in four different wavelengths

This experiment was designed to determine whether multi-spectral photography can be effectively utilised for earth resources programmes such as agriculture, forestry, geology, oceanography, hydrology, and geography. The results will help to refine the instruments for the Earth Resources Technology Satellite (ERTS), due for launch in 1972, Landsat, and techniques for multi-spectral photography to be conducted aboard the Skylab space station in the early 1970s.

Altogether 127 complete four-frame sets of photographs were taken over California, Texas, other areas of the southern United States, Mexico, the Caribbean and the Cape Verde Islands. Astronauts also took more than 1,100 standard Earth observation photographs of targets around the world, using colour and colour infrared film and a handheld Hasselblad camera.

Apollo-9 astronauts' colour photograph of the North Carolina coast and a colour infra-red view of California's Salton Sea

Coming Home
Apollo -9 returned to Earth on 13 March (the 14th for us here in Australia), the tenth day of the mission. Re-entry was delayed by one revolution due to heavy seas in the primary recovery area, but Gumdrop splashed down safely in the Atlantic, within three miles of the recovery ship, the USS Guadalcanal, after a mission totalling 241 hours, 53 seconds – just 10 seconds longer than planned!

On board the recovery ship, the crew were treated to a share of a 350-pound cake baked in their honour. Now safely back in Houston for their flight debriefings, NASA’s attention – and the world’s – is already turning to Apollo-10, due to fly in May to test the LM around the Moon!

Ready for the Next Steps
While Apollo-9 might not have seemed as exciting a mission as Apollo-8’s epic lunar voyage, it was critical because it has simulated in Earth orbit, as far as possible, many of the conditions that the astronauts and their equipment will face when the lunar landing attempt is made. Beyond that first landing and its successors, there is the Apollo Applications Programme, and other developments such as the Skylab manned earth orbiting workshop. Everything that has been learned in space with Apollo-9 will be useful sooner or later in future space activities!

And you can bet we'll be covering each and every one of them here on the Journey…

Apollo-9 view of the Moon


[January 24, 1968] On Track for the Moon (Apollo 5 and Surveyor 7]




by Kaye Dee

As we approach the first anniversary of the shocking loss of the crew of Apollo 1, the success of the recent Apollo 5 mission reminds us that the spirit of Grissom, White and Chaffee lives on as NASA continues developing and testing the technology to make a manned lunar landing a reality.

Apollo 1's Legacy
Although the fire that engulfed Apollo 1 and killed its crew destroyed its Command Module, the accident took place on the launchpad during a launch simulation, and fortunately the Saturn IB booster intended to loft that mission into orbit remained undamaged. Because that AS-204 vehicle was the last Saturn IB with full research and development instrumentation, NASA decided that this rocket would be re-assigned to Apollo 5, the much-delayed first test flight of the Lunar Module – the spacecraft essential for successfully landing astronauts on the Moon – while manned Apollo missions continue on hold.

From LEM to LM
The spacecraft we now call the Lunar Module (LM) became part of the Apollo programme in 1962, when NASA decided to adopt the technique of lunar orbit rendezvous (LOR) for its Moon landing missions. First proposed in 1919 by Ukrainian engineer and mathematician Yuri Kondratyuk, the LOR technique uses two spacecraft that travel together to the Moon and then separate in lunar orbit, with a lander carrying astronauts from orbit to the Moon’s surface. The LOR method allows the use of a smaller and lighter lander than the large, all-on-one spacecraft originally proposed for Apollo, and also provides for greater flexibility in landing site selection.

An early diagram comparing the size of a lunar landing vehicle using the Direct Ascent method of reaching the Moon and a LOR lunar excursion vehicle

The version of lunar orbit rendezvous suggested to NASA by engineer John C. Houbolt called for a landing vehicle consisting of two parts: a landing stage, that would accomplish the descent from orbit and remain on the Moon’s surface, and an ascent stage that would carry the astronauts back to the main spacecraft in orbit. This design gave us the Command Service Module as the Moon orbiting spacecraft, and what was originally called the Lunar Excursion Module (LEM, pronounced as a word, not as the individual letters) as the vehicle that would land astronauts on the Moon.

Dr. Houbolt illustrating the main spacecraft needed for his Lunar Orbit Rendezvous proposal for the Apollo programme

In June 1966, NASA changed the name to Lunar Module (LM), eliminating the word “excursion”. My friends at the WRE tell me that this was because there were concerns that using “excursion” might make it sound like the lunar missions were frivolous, and so reduce support for the Apollo programme! Despite the official name change, the astronauts, as well as staff at Grumman, still call it “the lem”, which certainly feels easier to say.

Delays…Delays…
However, the two-stage LEM/LM has proved much harder to develop and manufacture than the contractor Grumman originally anticipated, because of the complexity and level of reliability required of the hardware. Originally, NASA planned for the automated test flight of LM-1, the first Lunar Module, to occur in April 1967, but the delivery of the spacecraft was repeatedly delayed: the two stages of LM-1 did not arrive at Cape Kennedy until late June last year.

The separately-crated stages of LM-1 arriving at Kennedy Space Centre on board a Super Guppy cargo plane. The stages were mated to each other four days later

A team of 400 engineers and technicians then checked out the spacecraft to ensure that it met specifications. The discovery of leaks in the ascent stage propulsion system meant that the ascent and descent stages were demated and remated multiple times for repairs between August and October. LM-1 was finally mounted on its Saturn IB booster on 19 November and a launch date was set for the latter part of January 1968.

LM-1, encased in its SLA, being hoisted up for mounting on its launch vehicle

Lift Off at Last!
Although the launch was delayed for 10 hours when the countdown was held up by technical difficulties, Apollo 5 finally lifted off on 22 January 1968 (23 January for us here in Australia). The mission was designed to test the LM's descent and ascent propulsion systems, guidance and navigation systems, and the overall structural integrity of the craft. It also flight tested the Saturn V Instrument Unit.

Because they would not be needed during the Apollo 5 test flight, LM-1 had no landing legs, which helped to save weight. NASA also decided to replace the windows of LM-1 with aluminium plates as a precaution, after one of the windows broke during testing last December. Since the mission was of short duration, only some of LM-1’s systems were fully activated, and it only carried a partial load of consumables. 

LM-1's "legless" configuration is clearly seen in this view of it during checkout at Kennedy Space Centre

The Apollo 5 flight did not include Command and Service Modules (CSM), or a launch escape tower, so pictures of the launch vehicle show it to look more like its predecessor AS-203 than AS-202, which tested the CSM. The Apollo 5 stack had an overall height of 180ft and weighed 1,299,434 lbs. The LM was contained within the Spacecraft Lunar Module Adapter (SLA), located just below the nose cap of the rocket. The SLA consists of four panels that open like petals once the nose cap is jettisoned in orbit, allowing the LM to separate from the launcher.

The Saturn IB worked perfectly, inserting the second stage and LM into an 88-by-120-nautical-mile orbit. After the nose cone was jettisoned, LM-1 coasted for 43 minutes 52 seconds, before separating from the SLA into a 90-by-120-nautical-mile orbit. NASA’s Carnarvon tracking station in Western Australia tracked the first six orbits of the mission, while the new Apollo tracking station at Honeysuckle Creek, near Canberra, followed LM-1’s first orbit.

Putting LM-1 Through its Paces
Since it had no astronaut crew, the LM-1 test flight had a mission programmer installed, which could control the craft remotely. The first planned 39-second descent-engine burn commenced after two orbits, only to be aborted by the Apollo Guidance Computer after just four seconds, as the spacecraft was not travelling at its expected velocity. Exactly why this occurred is now being investigated. Of course, if there had been a crew onboard, the astronauts would probably have been able to analyse the situation and decide whether the engine should be restarted.

Instead, Mission Control, under Flight Director Gene Kranz, decided to conduct the engine and "fire-in-the-hole" tests under manual control, as without these test firings the mission would be deemed a failure. The "fire in the hole" test verified that the ascent stage could fire while attached to the descent stage, a procedure that will be used to launch from the Moon’s surface, or in the event of an aborted lunar landing. It involves shutting down the descent stage, switching control and power to the ascent stage, and firing the ascent engine while the two stages are still mated.

Apollo 5 Flight Director Gene Kranz (right) with future Lunar Module crew Astronauts McDivitt (left) and Schweickart (centre) discussing LM-1's control issues

Both the ascent and descent engines were fired multiple times during the flight to demonstrate that they could be restarted after initial use. Eight hours into the mission, a problem with the guidance system did cause the ascent stage to spin out of control, but the vital engine test burns had been completed by then. LM-1 also demonstrated its ability to maintain a stable hover, and the guidance and navigation systems controlled the spacecraft's attitude and velocity as planned.

At the conclusion of the flight testing, the separated ascent and descent stages were left in a low orbit, with the anticipation that atmospheric drag would naturally cause their orbits to decay so that the craft would re-enter the atmosphere. The ascent stage re-entered and was destroyed on 24 January, but as I write the descent stage is still in orbit.

Another Step on the Road to the Moon
NASA considers that the LM performed well during its test flight, and have deemed Apollo 5 a success. One wonders now if the second unmanned test flight with LM-2, planned for later this year, will need to go ahead. NASA also plans to return astronauts to space with a test flight of the redesigned Command Module in September this year. Once that goal is accomplished, every part of the Apollo system will have been tested in spaceflight and it will finally be “Go!” for astronauts to shoot for the Moon. I can’t wait!

Lunar map showing the landing sites of all the successful Surveyor missions

So Long Surveyor!
As the Apollo programme powers forward, the last of NASA’s automated lunar exploration programmes is coming to an end, with Surveyor 7 now in operation on the Moon. The Surveyor project was developed with the goal of demonstrating the feasibility of soft landings on the Moon's surface, ensuring that it would be safe for Apollo crews to touch down in their Lunar Modules. The Surveyor landings have complemented the Lunar Orbiter programme (which drew to a close in the latter part of last year), which imaged the Moon from orbit, mapping the lunar surface and providing detailed photographs of many proposed Apollo landing sites.

Making It Safe for a LM Landing
Of the seven Surveyor missions, five achieved their objectives, returning valuable data and images from the lunar surface. Surveyor 1, launched on 30 May (US time) in 1966, was the first American spacecraft to soft land on the Moon (following the successful landing of the USSR’s Luna 9 on 31 January that year), returning 11,237 images of the lunar surface. Unfortunately, its successor, Surveyor 2, failed in September 1966, impacting onto the lunar surface when a malfunction of the guidance system caused an error in the mid-course correction as it travelled to the Moon.

Surveyor 1's panorama of the lunar surface, which captured its shadow, cast by the light of the Earth

Surveyor 3, which lifted off on 17 April 1967, was the first to conduct in-situ experiments on the lunar soil, using its extendable arm and scoop. The spacecraft also returned over 6,000 images, including the famous "Surveyors Footprint" shot, showing its footpad on the lunar surface. The probe had a lucky escape as it tried to land: a problem with its descent radar caused the descent engine to cut off late, resulting in the lander bouncing twice on the lunar surface before settling down to a final safe landing!

Surveyor 3's footprint and footpad on the lunar surface, showing how it bounced on landing. The extendable arm and scoop are visible on the left of the picture

Just three months later, in July, Surveyor 4 was not so lucky. After a textbook flight to the Moon, contact was lost with the spacecraft just 2.5 minutes before touchdown in the Sinus Medii (Central Bay) region and it crashed onto the lunar surface. It’s believed that the solid-fuel descent engine may have exploded.

Launched on 8 September, Surveyor 5 also encountered engine problems on descent to the lunar surface, with a leak in the spacecraft's thruster system. Fortunately, it survived to make a safe landing and returned over 20,000 photographs over three lunar days. Instead of a sampler arm, Surveyor 5 carried an alpha backscattering experiment, and had a bar magnet attached to one landing pad. It carried out the first off-Earth soil analysis and made one of the most significant finds of the Surveyor missions — that the Moon's surface is likely basaltic, and therefore suitably safe for human exploration.

Surveyor 5's alpha backscattering experiment, sometimes described as a chemical laboratory on the Moon

Surveyor 6 landed safely near the Surveyor 4 crash site in November 1967 carrying an instrument package virtually identical to Surveyor 5. The spacecraft transmitted a total of 30,027 detailed images of the lunar surface, as well as determining the abundance of the chemical elements in the lunar soil. As an additional experiment, Surveyor 6 carried out the first lift-off from the Moon. Its engines were restarted, lifting the probe 12 ft above the lunar surface, and moving it 8 ft to the west, after which it landed again safely, and continued its scientific programme. 

Surveyor 7 – a Last Hurrah!
The successful completion of the Surveyor 6 mission accomplished all the goals that NASA had set for the Surveyor programme as an Apollo precursor. The JPL Surveyor team therefore decided that for the final mission they would aim for a riskier landing site, in the rugged highlands near the Tycho Crater. The engineers gave Surveyor 7 a less than 50-50 chance of landing upright due to the rough terrain in the area!

Tycho crater was the challenging landing site for NASA's last Surveyor mission

Launched on 7 January, Surveyor 7 is the last American robot spacecraft scheduled to land on the Moon before the Apollo astronauts. Its instrument package combines all the experiments used by its predecessors, in order to determine if the rugged terrain would be suitable for a future Apollo landing site.

During its first lunar day, the spacecraft’s camera has returned more than 14,000 images, including some views of the Earth! One of Surveyor 7’s innovations is the use of mirrors to obtain stereoscopic lunar photos. Laser beams directed at the Moon from two sites in the United States have also been recorded by cameras aboard Surveyor 7.

A view of the Earth captured by Surveyor 7's camera

Getting a Scoop
Surveyor 7’s versatile soil mechanics surface sampler is a key instrument on this mission. Designed to pick up lunar surface material, it can move samples around while being photographed, so that the properties of the lunar soil can be determined. It can also dig trenches up to 18 inches into the lunar surface to determine its bearing strength and squeeze lunar rocks or clods. The sampler is a scoop with a container which can be opened or closed by an electric motor. The scoop has a sharpened blade and includes two embedded magnets, to search for ferrous minerals and determine the magnetic characteristics of the lunar soil. So far, the moveable arm and scoop have performed 16 bearing tests, seven trenching tests, and two impact tests.

Only a few Surveyor 7 pictures are currently available, but this view of Surveyor 3 digging a trench into the Moon's surface shows how the scoop carries out this task

The scoop is mounted below the spacecraft’s the television camera so that it can reach the alpha-scattering instrument in its deployed position and move it to another selected location. In fact, the scoop helped to free the alpha-scattering instrument when it failed to deploy on the lunar surface. It has also been used to shade the alpha-scattering instrument and move it to different positions to evaluation other surface samples. During 36 hours of operation between January 11 and January 23, 1968, the sampler has performed flawlessly. Soil analyses have been conducted, as well as experiments on surface reflectivity and surface electrical properties. 

Surveyor 7 is now “sleeping” through its first lunar night. If it survives this period of intense cold, hopefully it will continue to produce significant results during its next lunar day. But if it doesn’t, the scientists and engineers at NASA’s Jet Propulsion Laboratory are already describing the Surveyor programme as a “treasure house of information for landing a man on the Moon before the end of this decade”. This has to be a fitting epitaph for any space mission.