February 17 – Icy you!

Today’s factismal: The world’s first weather satellite was launched in 1959.

Whenever you do something new, you inevitably make a few mistakes. It was true when you were learning to drive, it was true when you were learning to date, and it was very true when the United States started launching weather satellites.

The USA’s first attempts to launch a satellite were complete disasters. The Vanguard TV3 rose four feet into the air and then exploded, live on television. Its backup also failed. We finally managed to get a satellite into orbit with Explorer 1, but its long thin shape caused it to tumble erratically, making the data almost useless. Four more launch failure followed before we managed to get the world’s first weather satellite into orbit with Vanguard 2.

Backup for the Vanguard 2 satellite, on display at Goddard Space Flight Center (Image courtesy NASA)

Backup for the Vanguard 2 satellite, on display at Goddard Space Flight Center (Image courtesy NASA)

The satellite was intended to measure cloud cover and send the data back via a radio beacon. Thanks to its spherical shape (one of the lessons learned from the Explorer 1 debacle), Vanguard 2 would spin in a regular pattern, allowing it to ‘read’ the amount of cloud cover using two photocells. Unfortunately, the scientists could not control which way the satellite spun and as the experiment progressed, the satellite precessed and the spin direction changed. After nineteen days, instead of spinning like a wagon wheel rolling over the Earth, it twirled like a top. As a result, the data from the optical scanner was practically useless.

But the experiment wasn’t a complete failure. The satellite was also designed to measure minute changes in the Earth’s atmosphere, which would drag on the satellite as it orbited. By using a simple telescope and measuring how much extra time it took for Vanguard 2 to arrive at a given location, scientists could estimate how the density of the atmosphere changed. That part of the experiment worked perfectly, and is still working today.

It would take another ten months and several more failures before a completely successful weather satellite (the TIROS 1) would be launched. But the lessons that we learned from those failures have helped us build the largest and most complete set of operating satellites today.

If you’d like to help scientists as they ground-truth satellite observations, then consider joining the Citizen Weather Observer program:
http://wxqa.com/

2 thoughts on “February 17 – Icy you!

  1. Pingback: August 19 – Say cheese! – Little facts about science

  2. Pingback: August 19 – Say cheese! | Little facts about science

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s