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.

September Flickr Photo of the Month: Baby Alligators!

_DSC8853_R1_C1BM-LR
_DSC8853_R1_C1BM-LR by Mark L 2010.
Shared with permission.

There are some amazing photographers that wander the halls of HMNS – as well as our satellite facilities in the Sugar Land area. When we’re lucky, they share what they capture in our HMNS Flickr pool. Each month, we highlight one of these photos here on the blog.

This month, we’re featuring a photo from Mark L 2010, taken in Brazos Bend State Park – home to the Museum’s George Observatory. Spending the day there wildlife spotting is a perfect lead in to stargazing at the Observatory on a Saturday night. And as you can see – the animals are really cool!

Here’s what Mark had to say about his photo:

On Labor Day, 2011, we visited Brazos Bend State Park to take a look around and shoot a few photos. Just beyond the shore line of 40 Acre Lake against the fishing pier we saw a dozen or so baby alligators. The duck weed coated them completely, making an interesting sight.

Maybe more striking was the fact that as they were sleeping in the sun they were laying on one another much like you would expect of puppies. It was just a nice view of young wild life. We all wish our area could break out of the grip of this destructive drought, but it is surprising how beauty remains available in this park. Thanks to all who participate in making it available to the rest of us.

Inspired? Most of the Museum’s permanent galleries are open for photography, and we’d love for you to share your shots with us on Flickr, Facebook or Twitter. Check out the HMNS photo policy for guidelines.

“Solve It!” Crime Lab Family Event

Today’s post is by Sibyl Keller, Director of Programming at the Houston Museum of Natural Science in Sugar Land.

If you haven’t gotten the chance to check out the newest exhibition at HMNS at Sugar Land – October 1st is the day to mark your calendar!  Crime Lab Detective entered the halls at the Museum September 3rd and since has captured the fascination of visitors of all ages.

Crime Lab Detective | HMNS at Sugar Land
Crime Lab Detective at HMNS at Sugar Land

From 11 am until 2 pm on Saturday, October 1st – “Solve It!” Family Event begins even before you enter the Museum! 

Crime Lab Detective | HMNS at Sugar Land
Some of the evidence you can find in Crim Lab Detective. Now open at
the Houston Museum of Natural Science in Sugar Land.

Not to make a scene – but more as a celebration of joined forces of local law enforcement agencies, your discovery begins with an incredible line-up of emergency vehicles in the Vehicle Exploration Station located in the front parking lot of the Museum!

As you enter the Museum – members of the Fort Bend Sheriffs Department, the Office of Emergency Management, the Sugar Land Police Department and the Sugar Land Fire Department – will be on hand for demonstrations and to answer your many questions and to show off the crime fighting techniques used in our community.

After your visit with our community crime fighters and life savers, you then get to take the opportunity to try your own hand at crime scene investigation in visiting our new exhibit, Crime Lab Detective!

Crime Lab Detective | HMNS at Sugar Land
Members of Sugar Land’s First Responders will be at
the Houston Museum of Natural Science at Sugar Land on October 1.

In addition, the third floor conference room will be transformed into a Junior Investigation Laboratory set up inside the museum, featuring crime-busting activities and CSI crafts – fun for the whole family!

Crime Lab Detective | HMNS at Sugar Land
Sugar Land Fire Department Fire Truck

This event is ticketed separately from general admission to the museum.  Tickets include an admission to our traveling exhibit, Crime Lab Detective, and to the Junior Investigation Laboratory, as well as entry into the Vehicle Exploration Station.

Cockrell Butterfly Center Fall Plant Sale Oct. 8!

This time of year, gardening can make you feel as hot as Priscilla Queen of the Desert

With water restrictions and heat advisories, who wants to get into that mess? The drought and high temperatures have also caused butterflies to suffer, leaving their numbers well below normal for the season. In addition to the gardens we plant to supplement their diet, butterflies rely on native plants throughout their lifecycle. The lack of rain has caused the wildflowers either to have a very short blooming period, or not bloom at all. That means a decrease in nectar for butterflies. Native host plants as well are suffering in the dry heat, leaving caterpillars short of food as well. Triple digit temperatures cause female butterflies to not lay eggs and in general cause the overall populations to languish.

But, there is good news.

Soon the triple digits should be a thing of the past and we can all get outside and start tending our gardens again instead of watching through the window as they shrivel. The butterflies will be back as well and we need to be ready for them.

HMNS Fall Plant Sale
Cockrell Butterfly Center Fall Plant Sale Saturday, October 8

If your garden needs perking up, head over to the Cockrell Butterfly Center’s Fall Plant Sale on Saturday, October 8th, from 9 to 11am, on the 7th level of the parking garage at the Houston Museum of Natural Science. We will have a wide variety of host and nectar plants to attract butterflies, bees and hummingbirds to your garden.

HMNS Fall Plant Sale
The Cockrell Butterfly Center is the perfect place to see gorgeous,exotic butterflies – but you can help
preserve these fragile wonders by creating a butterfly habitat for local species
in your own backyard.

Check out the list of available plants for more information.

Here are some tips for attending the plant sale:

1. Get there early. This year our sale is only from 9 to 11 am.
2. Bring a wagon to cart around your goodies.
3. We take cash, check and credit cards.