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.

LEGO Is Launching an Official International Space Station Set

LEGO
LEGO

Not everyone can live out their childhood dreams of floating around in space aboard the International Space Station, but now you can at least construct a toy version of it for your own house.

Next month, LEGO is releasing an impressive model of the International Space Station as part of its Ideas program, which produces designs that were suggested by fans. This one was submitted three years ago by Christoph Ruge.

LEGO ISS
LEGO

According to TechCrunch, the kit includes the ISS, a dockable space shuttle, two astronaut figurines, and a satellite that you can “deploy” with the robotic Canadarm2 (which is used to capture and repair satellites on the ISS). It also comes with a display stand, so you can make it the eye-catching centerpiece of your coffee table if it happens to match your living room decor.

The ISS might not look as formidable as the life-size model of astronaut Buzz Aldrin that LEGO builders created last year, but that doesn’t mean it’s not difficult to construct—the 864-piece set is labeled for kids ages 16 and older.

LEGO ISS
LEGO

Having said that, it doesn’t mean that younger kids can’t help out with the assembly, or at least play with it once it’s complete. At about 7 inches high, 12 inches long, and 19 inches wide, the station could inspire the next generation of space explorers.

The $70 kit will be available on February 1 in LEGO stores or the LEGO website.

[h/t TechCrunch]

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A Snow Moon Will Light Up February Skies

makasana, iStock via Getty Images
makasana, iStock via Getty Images

February is the snowiest month of the year in many parts of the U.S., but on February 9, consider braving the weather outside to look up at the sky. That Sunday morning, the only full snow moon of the year will be visible. Here's what you need to know about the celestial event.

What is a snow moon?

If you keep track of the phases of the moon, you may already know that the full moon of each month has its own special name. Following January's wolf moon lunar eclipse is a snow moon in February. The name snow moon is said to have originated with Native American tribes, and it refers to the heavy snowfall that hits many parts of North America in February.

According to The Old Farmer's Almanac, different tribes had different names for February's full moon. The Wishram people named it the shoulder to shoulder around the fire moon and the Cherokee people called it the bone moon because animal bones were sometimes their only source of nutrition in the dead of winter. Snow moon is the name that's most commonly used by almanacs today.

When to See the Snow Moon

The moon will enter its next full phase the morning of Sunday, February 9. The snow moon will be at its fullest at 2:34 a.m. EST, but if you're not willing to stay up that late, it's still worth looking up. The previous evening—Saturday, February 8—the moon will be 99 percent illuminated on the East Coast. Check your local weather forecast and find a spot with clear skies to get the best view of the wintertime spectacle.

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