
by Kaye Dee
A recent picture of Mars, taken with the new 88-inch telescope on Mount Mauna-kea, Hawaii
Through a Window, Quickly
This year Mars is making its closest approach to the Earth since 1956, reducing the travel time to reach the Red Planet. Now that the launch window for Mars transit has opened, both the United States and the Soviet Union have wasted no time taking advantage of it, each nation sending a pair of spacecraft towards the Red Planet this past month. Once again, The Traveller has kindly given me a space to provide an update on these next steps in the exploration of the Solar System.
Not Plain Sailing
NASA was the first off the mark, with the 8 May (US time) launch of Mariner-8 (also known as Mariner-H), the first of the twin Mariner Mars '71 Mission spacecraft. The Mariner Mars '71 project was planned to consist of two identical spacecraft, each of which would go into orbit around Mars, performing separate, but complementary, missions.
Unfortunately, Mariner-8 didn’t even make it to low Earth orbit, with the upper stage of its Atlas-Centaur launch vehicle tumbling out of control and dumping the spacecraft into the Atlantic Ocean about 350 miles north of Puerto Rico.
The accident investigation has already discovered the cause of the vehicle loss: a malfunction in the pitch rate gyro amplifier.

Second Time Lucky
But at least the second half of Mariner Mars ’71 is proceeding. Mariner-9’s launch was delayed while NASA investigated the loss of Mariner-8, but just a few hours ago as I write this, Mariner-9 (alias Mariner-I) has launched successfully from Cape Kennedy on 30 May and is now on its way to Mars. The space agency is also hoping that it might be able to pull together a back-up mission before the Mars launch window closes, to join Mariner-9 as a replacement for Mariner-8. However, if that doesn’t happen, plans are already being made to combine as much as possible of Mariner-8’s planned observations into Mariner-9’s mission profile.
The current plan is for Mariner-9 to operate for a minimum of 90 days in Mars orbit gathering data on the composition and characteristics of the atmosphere and the topography and characteristics of the planet’s surface. The spacecraft is expected to take about 6,500 photographs of Mars during its first 90 days in orbit.
A full-size display model of the Mariner-9 probe now on its way to Mars. The lost Mariner-8 was identical
Red Stars to the Red Planet
Seven years after its first Mars mission (Mars-1), the Soviet Union is off to a better start than NASA, with both its Mars spacecraft (Mars-2 and Mars-3) safely on their way to the Red Planet – although it has been suggested that Cosmos-419, launched on May 10, may also have been a Mars mission that failed to leave Earth orbit. Speculation is that this spacecraft could have been intended to steal the honour of the first spacecraft into Mars orbit ahead of the Mariner probes by taking a slightly faster trajectory.
As ever with Soviet space missions, very little information has so far been forthcoming about these Mars probes. Mars-2, launched on 19 May, is reported by the TASS news agency to weigh around 10,250 lb, making it considerably larger than the USSR’s most recent Venus probe, Venera-7 (which weighed in at 2,602 lb) and about five times heavier than Mariner 9.
A photo provided by my friends at the Weapons Research Establishment, which is said to show the Mars-2 spacecraft. The "conical hat" at the top of the probe may be the heatshield for a landing vehicle carrying a small rover.
A "Mars Walker"?
Mars-3, which launched on 28 May, would appear to be very similar, if not identical, to Mars-2. TASS has indicated that the two Mars missions might help to clarify whether life might exist on Mars and in what form, as well as investigating the structure of the Martian atmosphere and the nature of the so-called Martian "canals" (although the images from Mariners 4, 5 and 6 already indicate that they do not exist at all).
TASS has not indicated whether Mars-2 or 3 will attempt to land on Mars or just orbit the planet, like Mariner-9, but there are rumors that one of the two probes could be carrying a “Marsokhod” – a vehicle similar to Lunokhod-1 to explore the Martian surface.

This isn't a Russian probe; it's a Mars Rover prototype recently developed by Rensselaer Polytechnic Institute students and faculty—not yet flown of course
Mariner 9 is following approximately the same flightpath as the two Soviet spacecraft, and all three are expected to arrive at Mars in November. Watch out for our mission updates once they arrive in Martian orbit!
And meanwhile, now it's back to The Traveller for his next reviews.

by Gideon Marcus
Science Fact vs. Science Fiction
Isaac Asimov famously gave up writing science fiction vocationally when Sputnik went up in 1957—real-world advances in science had outstripped our imagination when it comes to delivering an exciting story. Well, nothing proves the point better than contrasting the exciting news Kaye just relayed to you and this month's Analog…

Cover by Kelly Freas
Continue reading [May 31, 1971] Red Planet, Here We Come! (US and Soviet Mars Missions) and the June 1971 Analog →