Dawn launch postponed to September

The entire universe in blog form
July 8 2007 5:26 PM

Dawn launch postponed to September

Sigh. This poor mission, which has certainly suffered its share of slings and arrows, has had its launch postponed until September. The launch slip last week messed things up a bit to start, of course. And now the launch constraints butt up against the launch of the Phoenix Mars probe in early August. Worse, the orbital path of Dawn is somewhat complicated -- it needs to slip into orbit around two separate asteroids, making launch windows tight.

Think of it this way: you are in a car doing laps at a racetrack at 100 kph. You have a bow and arrow, and you have to shoot at a target off to the side. You can wait until the last millisecond and shoot the arrow quickly, or give yourself an extra half-second and shoot the arrow a little more slowly. That range in time is your launch window.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Advertisement

Oh -- did I mention the target is moving? And oh -- you have to hit a bullseye within a tenth of a millimeter of the exact center of the target. And oh -- later on there is a second target you have to hit as well, starting from the first target. That second target is moving too.

Have fun!

That's why the launch constraints on these missions can be so severe. Things in the solar system have to be just so.

So: next time you want to complain about NASA letting launches slip, or that they are a bunch of boobs, try that little experiment above and see how well you do. Those guys can thread a needle from millions of kilometers away, and they do this sort of thing all the time.

So Dawn's launch will be in September, when the targets line up well again. Until then, we have Phoenix to look forward too, and that's a fantastic mission as well.

TODAY IN SLATE

Politics

Meet the New Bosses

How the Republicans would run the Senate.

The Government Is Giving Millions of Dollars in Electric-Car Subsidies to the Wrong Drivers

Scotland Is Just the Beginning. Expect More Political Earthquakes in Europe.

Cheez-Its. Ritz. Triscuits.

Why all cracker names sound alike.

Friends Was the Last Purely Pleasurable Sitcom

The Eye

This Whimsical Driverless Car Imagines Transportation in 2059

Medical Examiner

Did America Get Fat by Drinking Diet Soda?  

A high-profile study points the finger at artificial sweeteners.

The Afghan Town With a Legitimately Good Tourism Pitch

A Futurama Writer on How the Vietnam War Shaped the Series

  News & Politics
Photography
Sept. 21 2014 11:34 PM People’s Climate March in Photos Hundreds of thousands of marchers took to the streets of NYC in the largest climate rally in history.
  Business
Business Insider
Sept. 20 2014 6:30 AM The Man Making Bill Gates Richer
  Life
Quora
Sept. 20 2014 7:27 AM How Do Plants Grow Aboard the International Space Station?
  Double X
The XX Factor
Sept. 19 2014 4:58 PM Steubenville Gets the Lifetime Treatment (And a Cheerleader Erupts Into Flames)
  Slate Plus
Tv Club
Sept. 21 2014 1:15 PM The Slate Doctor Who Podcast: Episode 5  A spoiler-filled discussion of "Time Heist."
  Arts
Television
Sept. 21 2014 9:00 PM Attractive People Being Funny While Doing Amusing and Sometimes Romantic Things Don’t dismiss it. Friends was a truly great show.
  Technology
Future Tense
Sept. 21 2014 11:38 PM “Welcome to the War of Tomorrow” How Futurama’s writers depicted asymmetrical warfare.
  Health & Science
The Good Word
Sept. 21 2014 11:44 PM Does This Name Make Me Sound High-Fat? Why it just seems so right to call a cracker “Cheez-It.”
  Sports
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.