Landing In Sea Logical End To U.S. Spaceflights

Press, Volume CIX, Issue 32166, 9 December 1969, Page 23

Landing In Sea Logical End To U.S. Spaceflights

The lightning discharge that scorched Apollo 12 just after lift-off raised questions about the weather restrictions which should apply when men are blasted into space. Ten days later the Apollo 12 splash-down was amid 12-foot waves.

The flight began and ended under the worst weather conditions of any American manned space mission to date.

for the space programme. The resulting litigation could drag on for years in a country like the United States.

The Atlantic Task Force is deployed near Cape Kennedy when every manned mission blasts into space and as there have been no aborted launchings their main activity has been the recovery of camera pods dropped from the lower stages of the booster vehicles. They then steam to the planned recovery area to await splashdown and their brief moment of glory when the eyes of the world are upon them. The Atlantic Task Force has retrieved 14 manned capsules in 15 attempts, but have never lost a spaceman. They could not avoid the loss of the Liberty Bell Mercury spacecraft which sank when Astronaut Virgil Grissom, later to die in an Apollo fire, accidentally blew open a hatch and flooded it The Pacific Task Force 130 has recovered seven manned spacecraft without loss. Most have been along what is known as the Mid-Pacific recovery line which will continue to be the prime splashdown area for all forthcoming Apollo missions to the Moon. Two other recovery lines in the Pacific together with one in the Atlantic and another in the Indian Ocean provide enough landing areas to permit an emergency return to Earth at almost any time from lunar orbit

On the other hand a similar occurrence in the Soviet Union would be all but forgotten a few weeks afterward. There would be little or no interruption to their space programme. It is therefore no wonder that the United States prefers to recover space capsules from the ocean while the Russians favour recoveries on dry land. Location Of Pads A final consideration is closely tied to the geographical location of the launching sites. All United States spacecraft are launched from pads near the coast of Florida, California or Virginia and for safety reasons are always aimed seawards. The three Soviet launch areas are well away from the coast. Consequently an abort during the boost phase must result in a wet landing for an American capsule and a dry landing in the Russian case.

Almost always it is possible to postpone the launching of a space mission until the weather improves. Landings are often much less flexible in timing. Once an Apollo expedition heads for home it is committed to splash into the ocean at a fairly precise time about three days later. For example Apollo 11 landed 73 seconds early; Apollo 12 was 14 seconds late—not bad for journeys of eight and 10 days total duration. However there is some flexibility in the location of the splashdown point The aerodynamic design of the Apollo capsule will permit it to overshoot by nearly 1500 miles if necessary to avoid a zone of bad weather. Taking advantage of this capability is one of the main reasons why the Americans favour ocean landings. On land an overshoot of 1500 miles could change the terrain of the landing area quite drastically. This is indeed what happened in the case of the Soviet spaceship Voshkod 2 which overshot its intended landing: site on the smooth Russian steppes and landed hundreds of miles further east on the steep slopes of the Ural mountains. The space-walker, Leonov, and his companion, Cpsmonaut Belyayev, spent a chilly night in the snow, until their rescuers reached them.

The United States Navy is charged with the responsibility for retrieving all American manned spacecraft and has organised two Task Forces for this purpose: Task Force 140 in the Atlantic and Task Force 130 in the Pacific.

Pacific Ideal There are other advantages to ocean landings. Since three quarters of the surface of our globe is water there is greater likelihood that the best landing site from trajectory considerations will lie in an ocean area. Because of its broad extent the Pacific Ocean is ideal as a target for a return trajectory from the Moon. This is a result of the everchanging orbital position of the Moon which decrees that the latitude of splashdown may vary up to thirty degrees north or south of the equator. It may sound rather complicated, but the splashdown point must be near the antipode of the Moon’s position at the time when the spacecraft rockets are fired for the return trip. The antipode lies on the continuation of the straight line joining the centres of the Moon and Earth at that moment. This determines the latitude of splashdown. The longitude depends on the time taken for the return journey, because the Earth is continuously rotating with respect to the lunar antipode. The recovery latitudes of Apollos 8, 10 and 11 were north of the equator because at the time the Moon was above our southern hemisphere. The opposite was true for Apollo 12. Apollos 7 and 9 did not go to the Moon. For recoveries from Earth orbit the requirements are rather different and the recovery areas may be more conveniently located, except when an emergency arises and a rapid return is called for. This happened in the case of Gemini 8, the only mission of the Gemini series to land in the Pacific Ocean. After completing the first successful docking of two space vehicles a thruster malfunction forced the command pilot, Neil Armstrong, to make an emergency re-entry and landing just south of Japan.

The last two of the Project Mercury spaceflights landed in the Pacific Ocean near Midway Island. The duration of each flight made it necessary to choose between the North Pacific Ocean, or the South Atlantic. In the latter case an: overshoot would have landed the Mercury capsule in the jungles of Africa, so the Pacific was preferred.

Diplomatic Factors Other important factors lie in the diplomatic sphere. Ocean landings avoid the need for recovery forces to trespass on foreign territories. Most member countries of the United Nations have, however, signed space treaties which recognise the need to assist spacemen in distress. But a more pressing issue rests in the problem of compensation for damage caused by space activities. Within national boundaries the situation depends largely on the type of government. Suppose the Americans normally recovered their space capsules from a landing area in the Arizona desert, but one day a 6-ton Apollo capsule overshot the landing area and fell on an inhabited area, killing several' civilians. In a democratic society the consequences could be disastrous