On This Day in 1962, NASA Launched and Destroyed Mariner 1

NASA // Public Domain
NASA // Public Domain

On July 22, 1962, NASA launched the Mariner 1 probe, which was intended to fly by Venus and collect data on its temperature and atmosphere. It was intended to be the first interplanetary craft—the first time humans had sent a space probe to another world. Unfortunately, NASA aborted the mission 293 seconds after launch, destroying the probe in the Atlantic. What happened?

First off, a bit of history. Mariner 1 was based on the pre-existing Block 1 craft used in the Ranger program, which was aimed at gathering data on our moon. Those early Ranger probes didn't do so well—both Ranger 1 and Ranger 2 suffered early failures in orbit. Mariner 1 was a modified version of the Ranger design, intended for a much longer mission to another planet. It lacked a camera, but had various radiometers, a cosmic dust detector, and a plasma spectrometer—it would be capable of gathering data about Venus, but not pictures per se.

The two previous Ranger missions had used basically the same launch system, so it was reasonably well-tested. The Ranger probes had made it into orbit, but had been unable to stabilize themselves after that.

Mariner 1 launched on the evening of July 22, 1963. Its Atlas-Agena rocket was aided by two radar systems, designed to track data on velocity (the "Rate System") and distance/angle (the "Track System") and send it to ground-based computers. By combining that data, the computers at Cape Canaveral helped the rocket maintain a trajectory that, when separated, would lead Mariner 1 to Venus.

Part of the problem involved in handling two separate radars was that there was a slight delay—43 milliseconds—between the two radars' data reports. That wasn't a problem by itself. The Cape computer simply had to correct for that difference. But in that correction process, a problem was hiding—a problem that hadn't appeared in either of the previous Ranger launches.

To correct the timing of the data from the Rate System—the radar responsible for measuring velocity of the rocket—the ground computer ran data through a formula. Unfortunately, when that formula had been input into the computer, a crucial element called an overbar was omitted. The overbar indicated that several values in the formula belonged together; leaving it out meant that a slightly different calculation would be made. But that wasn't a problem by itself.

The fate of Mariner 1 was sealed when the Rate System hardware failed on launch. This should not have been a fatal blow, as the Track System was still working, and Ground Control should have been able to compensate. But because that overbar was missing, calculations on the incoming radar data went wonky. The computer incorrectly began compensating for normal movement of the spacecraft, using slightly incorrect math. The craft was moving as normal, but the formula for analyzing that data had a typo—so it began telling Mariner 1 to adjust its trajectory. It was fixing a problem that didn't exist, all because a few symbols in a formula weren't grouped together properly.

Mariner 1's rocket did as it was told, altering its trajectory based on faulty computer instructions. Looking on in horror, the Range Safety Officer at the Cape saw that the Atlas rocket was now headed for a crash-landing, potentially either in shipping lanes or inhabited areas of Earth. It was 293 seconds after launch, and the rocket was about to separate from the probe.

With just 6 seconds remaining before the Mariner 1 probe was scheduled to separate (and ground control would be lost), that officer made the right call—he sent the destruct command, ditching Mariner I in an unpopulated area of the Atlantic.

The incident was one of many early space launch failures, but what made it so notable was the frenzy of reporting about it, mostly centered on what writer Arthur C. Clarke called "the most expensive hyphen in history." The New York Times incorrectly reported that the overbar was a "hyphen" (a reasonable mistake, given that they are both printed horizontal lines) but correctly reported that this programming error, when coupled with the hardware failure of the Rate System, caused the failure. The bug was identified and fixed rapidly, though the failed launch cost $18,500,000 in 1962 dollars—north of $150 million today.

Fortunately for NASA, Mariner 2 was waiting in the wings. An identical craft, it launched just five weeks later on August 27, 1962. And, without the bug and the radar hardware failure, it worked as planned, reaching Venus and becoming the first interplanetary spacecraft in history. It returned valuable data about the temperature and atmosphere of Venus, as well as recording solar wind and interplanetary dust data along the way. There would be 10 Mariner missions in all [PDF], with Mariner 1, 3, and 8 suffering losses during launch.

For further reading, consult this Ars Technica discussion, which includes valuable quotes from Paul E. Ceruzzi's book Beyond The Limits—Flight Enters the Computer Age.

22 Facts About the Solar System

Mental Floss via YouTube
Mental Floss via YouTube

So you want to know everything there is to know about the solar system? The first and most important question you might want to get out of the way is: what, exactly, isthe solar system? As Mental Floss editor-in-chief Erin McCarthy tells us, "It's a group of celestial bodies located within the Milky Way galaxy."

At the center of these bodies is the Sun, which is orbited by eight planets; more than 150 moons; and millions of meteoroids, comets, asteroids, and a handful of dwarf planets (sorry, Pluto). But it's the Sun—a.k.a. that shining, 4.5 billion-year-old star in the middle of it all—that accounts for 99 percent of the solar system's total mass. (Think about that the next time you're shading your eyes from its glare.)

In this all-new edition of The List Show, Erin is sharing nearly two dozen fascinating facts about our solar system, including the reasoning behind Pluto's demotion (blame it on Eris, the first known dwarf planet). For more out-of-this-world facts, you can watch the full episode below.

For more episodes like this one, be sure to subscribe here.

LEGO Built a Life-Sized Astronaut Model to Celebrate the 50th Anniversary of Apollo 11

The LEGO Group
The LEGO Group

The LEGO Group is honoring the 50th anniversary of the Apollo 11 mission in a way that only LEGO can: with a life-sized astronaut model constructed entirely from LEGO blocks.

The 6-foot-3-inch model matches the space suit worn on the Moon by astronaut Edwin “Buzz” Aldrin on July 21, 1969, down to the American flag patch on his left shoulder. The front of the helmet even mimics the well-known photo of Aldrin standing on the Moon’s surface, with his helmet reflecting his own shadow and fellow Moon-walker Neil Armstrong in the near distance.

The feat took a team of 10 designers and LEGO Master Builders 300 hours and 30,000 LEGO bricks to complete, and you can see it in person on Washington, D.C.’s National Mall as part of the Smithsonian’s National Air and Space Museum’s Apollo 50 Festival from July 18 to July 20.

Though the astronaut model is already complete, there’s still tons to build—during the festival, you can help Master Builders assemble mosaic backdrops of the Moon and Mars, and you can even lend a hand in the construction of a 20-foot-tall replica of NASA's Space Launch System rocket, the vehicle NASA is developing to potentially use to send humans to Mars in the future.

The LEGO Group is also displaying an 11-foot-tall replica of a rocket at the Ontario Science Centre in Canada from now through September 2. It contains not only an impressive 80,000 bricks, but also built-in lights, sound, and a fog machine to simulate a rocket launch.

Buzz Aldrin on the Moon
Buzz Aldrin walks on the Moon.
NASA, Wikimedia Commons // Public Domain

It’s all part of a LEGO initiative to inspire a new generation of children to be enthusiastic about—and personally involved in—the future of space exploration. In addition to its brick-based efforts, the company is currently partnering with Scholastic on a program to send 50 kids to NASA Space Camp next year. “We will continue to inspire children to dream about what’s possible and to grow up to pursue STEM careers, said Bettina Inclán, associate administrator for communications at NASA’s Washington, D.C. headquarters.

Check out LEGO’s space-related collections—featuring Mars exploration, women of NASA, a recreation of the Moon landing, and more—on its online store.

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