Ride on a Shooting Star: Space Fuel

After the decimation suffered during World War II, mankind took a look at all the new technologies he had created to fight the war and turned his gaze towards the stars. From the late 1940’s this onward and upward reach has helped to fuel the engines of our ingenuity, but what has fueled those stellar ambassadors that now dot our solar system and beyond.

654 - Galaxies - Seamless Texture
Creative Commons License photo credit: Patrick Hoesly

To move from the surface of the earth to this new ocean a rocket must be moving about 7 miles per second. That takes a lot of energy. Many different propellants have been used. The very first rocket fuels were a mix of kerosene and liquid oxygen. Alcohol, hydrogen peroxide, and liquid hydrogen have also been used, in addition to solid fuels. They can provide thrust without the need for all the refrigeration and containment equipment that some of the liquid fuels, such as liquid hydrogen and oxygen, require.

Once the probe is beyond the reach of the atmosphere there is no way to change what’s on board.

The probe cannot drop by the local Radio Shack and pick up a fresh pair of AA batteries. While the probe is being built on Earth, the engineers must make sure that they provide a source of power that will give the probe the right amount of power.

Too little power and the scientific instrumentation won’t work; too much power could over heat the probe. On board chemical batteries can be used, but they take space that could be used for scientific instruments. Solar panels can be used, but only up to a certain distance from the sun. Beyond the orbit of Jupiter, probes need an internal power supply that will last for years.

They use the heat from radioactive decay of fissionable isotope.

Sputnik 1 in Orbit Sep 10-4-57
Creative Commons License photo credit: FlyingSinger

Early probes like Sputnik and Explorer 1 used chemical batteries to power their systems. In March of 1958 Vanguard 1, the 4th artificial satellite and the 1st powered by solar power, was launched. Probes with solar panels have more space on board for scientific instruments than probes that use only chemical batteries. Probes sent into the inner solar system (sun to Mars) are almost all powered using solar arrays.

Mariner 2, the first USA probe to Venus, suffered the loss of one of its solar arrays, but because it was closer to the sun, it was able to operate using only one solar array. No American manned space craft have made use of solar arrays yet (the new Multi-Purpose Crew Vehicle may), the Russian Soyuz spacecraft have used them since 1967.

The International Space Station (ISS) is the largest man-made structure outside our atmosphere.

Larger than a football field (but smaller than a football pitch), this outpost orbits the earth every hour and a half. It is also powered completely by solar power. Past the atmosphere, solar power becomes more practical and more consistent (there is no night in space). Because of the orbital path of the ISS, it is eclipsed by the earth for 30 minutes out of every hour and a half. The station makes use of rechargeable batteries to make sure it is never without power.

From a Distance
Creative Commons License photo credit: Undertow851

As the probes go farther and farther away from the sun, the light that can reach them is less and less.

Until August of 2011, no probe to Jupiter had ever been powered just by solar panels. Juno, the latest probe to Jupiter, has the largest solar arrays given to a deep space probe and the first probe to Jupiter to use solar arrays.

Jupiter receives only 4% of the sunlight we enjoy on Earth. Advances in solar technology have now made it practical to use solar panels out 5 Astronomical Units (AUs) from the sun. All other deep space probes have used a radioisotope thermoelectric generator (RTG).

A RTG works by converting the heat from the decay of a radioactive fuel into electricity. American probes have been using Plutonium 238 (an isotope of Plutonium) since the late 1960’s. It has a half life of about 88 years. RTGs have powered all our interplanetary probes (the Voyagers and Pioneers and soon to be New Horizons). However, NASA has begun to run out of fuel for the RTGs and the creation of more is full of political and safety considerations.

There he goes, after an all day long work.
Creative Commons License photo credit: giumaiolini

The technology that we’ve made to go out to the ‘verse with will also help us here on the cool, green hills of earth. RGTs have been used, mainly by Russia, to provide power for off the grid light houses. Advances in solar panels for space are used down here on Terre Firma. With the reliably of solar power in space, there are even attempts to construct orbital solar collectors to beam down electricity. There will be from heaven to Earth more than is dreamt of.

Astronomy Day 2010

Todays blog post is from Cynthia Gustava, who is planning the events surrounding Astronomy Day 2010. Come down to the George Observatory this Saturday and learn all about astronomy and our amazing facility in Brazos Bend State Park

The George Observatory, a satellite facility of the Houston Museum of Natural Science, will again host its annual Astronomy Day activities. The event is this Saturday, Oct. 16, 2010.  We’ll officially open the doors to the public at 3 p.m., and events will begin to wind down at around 10:30 p.m.

Before opening the doors to the public at 3 p.m., we will be heading up a telephone contact with the International Space Station (ISS), which will be broadcast and recorded. The pass of the ISS is (at this writing) expected to be some time around 11:30 a.m. One scout troop and one school group coming in for an early Challenger Center mission will participate in this contact and ask questions of the ISS crew. We are encouraging all volunteers to be up on deck to listen to this special event, which will take approximately 10 minutes.

The observatory is home to three high-quality telescopes, including the multi-million dollar, 36-inch diameter Gueymard telescope, which is used regularly for scientific research. The 11-inch refractor mounted on one side of the Gueymard telescope was donated to the George Observatory by Preston and Donna Engebretson of Houston and has proven to be a wonderful addition to the retinue of telescopes housed in the domes. The 11” refractor telescope provides impressive views of planets and deep sky objects alike.

The astronomy clubs from Houston and Beaumont come together this one day of the year for the purpose of sharing with the general public as much information about astronomy as possible in one day. Local area amateur astronomers are part of the lecture agenda taking place indoors with talks starting at 4 p.m., and running every hour until 10 p.m. There are also outdoor presentations by amateur astronomers every half hour until dark, learning tools for the young and old, kid’s activities, face painting, button making, night sky constellation tours and the opportunity to impart your knowledge of night sky objects to the public. Tables will be set up in the downstairs lobby and foyer by HCC Southwest Campus, the Night Sky Network, Land Sea & Sky, Advanced Telescope Repair and the usual Astronomy “club” table. Be sure to visit the new NASA pop-up displays set up downstairs in the main area. These will display images and information on the ISS and the Hubble Space Telescope. The theme this year for the astronomy t-shirts, and for the entire event, will commemorate the 20th birthday of the Hubble telescope. 

Consider bringing your solar-filtered telescope to set up on the deck in the afternoon hours to provide safe viewing of the Sun. Also in the afternoon, a simulated spaceship flight to the Moon in the Challenger Center will be open to the public.

If you are new to the area, the George Observatory, located within Brazos Bend State Park, is about one hours’ drive southwest of Houston. The Brazos Bend State Park is a fascinating blend of lakes and trails, with alligators, small animals and wild birds of many types. The Park and the George Observatory can be reached in two ways. Maps and driving directions are available here.

We hope you can join us for a day of astronomy and fun!

Cynthia Gustava
Astronomy Day Coordinator

Science Doesn’t Sleep (9.8.08)

Bacteria loves milk.
Creative Commons License photo credit: IRRI Images

So here’s what went down after you logged off.

A NASA administrator insists he backs the upcoming retirement of the space shuttle (leaving the U.S. unable to send astronauts to the International Space Station)  – despite a leaked e-mail to the contrary. Oh – and, the BBC reports that Chinese astronauts (called yuhangyuan) will perform their first-ever spacewalk.

Got bacteria? New research indicates that you shouldn’t be washing your antibiotics down with milk.

Bad news for mathletes: using your brain might be making you fat.

NPR asks: Can physicists be funny? (The answer is YES.) Scientists at CERN are going through improv comedy training to help reassure the public that they’re not about to create a giant black hole that will swallow the Earth.

Arctic permafrost holds twice as much carbon as the atmosphere – making it a potential environmental threat. Good thing it’s not melting at a disturbingly fast pace.

Does the President need to be tech-savvy?

Science Doesn’t Sleep (9.4.08)

Released to Public: Astronaut Robert L. Curbeam, Jr., STS-116 Spacewalk (NASA)
“Houston…we’ve got a
SPAM problem.”
Creative Commons License photo credit:

So here’s what went down after you logged off.

There’s a new Manhattan floating around the Arctic – and it’s made of ice. Canada’s polar ice shelves are “crumbling at an alarming pace.” In other good news: sea levels will rise much faster than we thought.

It’s possibly the lamest thing ever done in space: yesterday, astronauts spent some time updating their antivirus software.

It was the fake mustaches that tipped them off. Up to 10 percent of Near Earth Objects are comets impersonating asteroids – and new research aims to unmask them.

It’s really, really big: a black hole as big as 50 billion suns.

The ocean has its own lakes – called meddies – and scientists are using oil industry tech to study them.