When Denver resident Doug Kacena was a freshman at the University of Colorado Boulder in 1994, his older sister, Melissa, asked for a favor.

I needed a whole bunch of hands to take measurements of bacteria every two hours, recalls Melissa Kacena, who was working on her masters degree at the same school.

The bacteria project wound up on Space Station Mir and Kacena went on to get her Ph.D. in aerospace engineering at CU Boulder and did post-doctoral work at Yale University. The younger Kacena? He dropped out of the molecular cellular developmental biology program to major in art. Hes now a ground-breaking abstract artist who recently challenged traditional artists to give him paintingsso he could paint over them.

More than 20 years later, Melissa Kacena asked her brother for another favor.

The siblings reunited ona project that is headed for space on Saturday. Melissa Kacenais currently in Cape Canaveral, Fla., prepping 40 micefor a trip to the International Space Station. Theyll be studied as part of a bone recovery experiment. She tapped herbrother to design the official patch for the teams space mission, the Rodent Research IV.

Doug Kacena

It was an incredible honor to be asked to do it, said Doug Kacena. I did it before anyone had a chance to rethink it.

Embroidered patches with personal stories have been a part of NASAs history since 1965. But most patches dont make it into the public eye or even NASA space stores andno one seems to know how many patches exist.

I would estimate about 200 to 250 total, and that doesnt take into account the patches designed by the customers (military, commercial and NASA) that rode on those launches, saidRobert Pearlman, editor at collectSPACE, which is full of key moments in space history.

The space agency lets mission participants design their own patches for team-bonding purposes, according to Bill Barry, NASAs chief historian. ButNASA only keeps track of patches fromofficial trips, which include all manned missions, shuttle launches and select others or about 160 since the first patch was used in 1965. NASA makes the taxpayer-funded designs available to the public, so anyone can create one. NASA prefers to stick to its blue and white logo.

NASAs view is that multiple images dilute the brand, Barry said. We use the NASA logo for all communication purposes.

But Barry understands the affinity for space mission patches.

When I was a kid back in the 60s, I had a complete collection of all the Apollo mission patches, Barry said. And I was crushed when I learned as an adult that they werent real. The crew-sized ones were bigger.

NASA

The custom began in 1965 with the Gemini 5. Astronauts Gordon Cooper and Charles Conrad were preparing for an eight-day orbit around Earth and wanted a Conestoga wagon and stenciled on the side, 8 Days or Bust, said Barry. Both of those guys were fun-loving characters. Lets put it that way.

NASA didnt want to risk criticism if the mission was shorter or longer than eight days. They approved the patch, but not the wording. That was covered up by a piece of white cloth. And from then on, space mission patches became a thing as long as NASA gave its approval.

But unofficial patches dont have to follow any guidelines since they are not used for official NASA communication, Barry said. There could be multiple patches for the same launch if multiple parties are involved.

Private companies like SpaceX and United Launch Alliance have made their own mission patches.Other government agencies that have launched satellites also have created patches, including the elusive U.S. National Reconnaissance Office.Theories abound as to what the secretive satellites were intended for, with mystery patches to boot. One patch for the NROL-35 mission has a purple-haired wizard holding a trident and ball of fire. Another, for a 2011 launch, shows a bird engulfed in flames with an American flag in the background and Latin words that translate to Better the devil you know, according to the Smithsonian.

NASA

The patch for the Space Shuttle Challenger STS-51-L mission included the names of all seven crew members, which included Ellison Onizuka, who graduated from CU Boulder, and Christa McAuliffe, the first teacher in space, The shuttle broke apart 73 seconds into mission, killing everyone on board.

NASA

The patch for the final flight of Space Shuttle Columbia STS-107 is shaped like a shuttle and includes the symbol for microgravity, g. Crew members included Kalpana Chawla, who earned her PhD from CU Boulder. The shuttle disintegrated on reentry to earth and all seven members were killed.

NASA

In 1965, Gemini 5 was the first NASA space mission to get an official patch. Astronauts Gordon Cooper and Charles Conrad, prepping for the 8-day orbit around earth, wanted a patch showing a wagon with the words "8 Days or Bust." NASA nixed the wording and from then on, allowed patches for missions as long as they received NASA approval.

Doug Kacena

Rodent Research IV is one of the projects heading to space on the SpaceX Dragon capsule, scheduled to launch Feb. 18, 2017 in Florida. Scientist Melissa Kacena, who is originally from Colorado, is sending 40 mice to the International Space Station to study how bones heal in a weightless environment. She asked brother Doug Kacena, a Denver artist, to design the patch.

CollectSpace.com

The Russian Soyuz TMA-17M mission patch paid tribute to NASA's Apollo 17 mission, said Soyuz commander Oleg Konenenko, according to space-news site CollectSpace.com.

CollectSpace.com

After comedian Stephen Colbert staged a write-in campaign to win a NASA poll, the comedian got his own patch, but not for any space mission. It's in honor of the ISS's new excercise machine: the Combined Operational Load Bearing External Resistance Treadmill, according to space news site CollectSpace.com.

One popular patch was worn by the crew that launched the Spirit and OpportunityMars rovers in 2003. Entertainment company Warner Bros. workedwith the Air Force to create patches for each rover, one featured Marvin The Martian, the other Daffy Duck as Duck Dodgers.

Even astronaut classes have their own patches, like the astronaut class of 1990. The 13th class played on the unlucky number by picking a black cat and calling themselves, the Hairballs.

Research teams like Rodent Research IV have jumped at the chance to design their own patches.

Provided by Melissa Kacena

That brings us back to Melissa Kacena, now a professor of orthopaedic surgery at Indiana University School of Medicine. Shes been working with her students for more than three years on a methodthat helps bone fractures heal while a person is weightless, via crutches or recuperating in bed. Thats hard to test with mice, who dont like to stay still even when asked nicely, she said.

Bone fractures actually heal better with exercise, which increases bone strength. But walking on a fracture doesnt help the bone-healing process if a metal or hardware implant is involved.

If all your body weight goes into the implant, it will eventually fail. You need the bone to start growing before the implant fails, she said.

With support from the U.S. Department of Defense, the project becomes the fourth to send mice into space. Astronauts at the space station will help with the research before sending everything back to Earth after four weeks.

Were going to learn so much about the bone-healing process, she said, important because theres a really good chance that astronauts will get a fracture if they go to Mars.

Astronauts lose about 1 to 3 percent of bone density each month in space, she said. A person with osteoporosis loses 1 percent a year. If you lose (bone mass) going to Mars, theres an increased risk of fractures. We need to know how to heal.

After asking her team to come up with patch designs, they turned to her brother, Doug, who created a fairly straightforward design.The Rodent Research IV patch shows a silhouette of a mouse, its tail tucked underneath a strand of DNA.A galaxy of stars is in the background while the SpaceX Dragon capsule floats near the patchs edge.

The embroidered patch is scheduled to hitch a ride Saturday on the SpaceX Dragon during its CRS-10 cargo resupply mission to the ISS, a trip originally set for last summer.

Before the group packed up its gear and headed to Florida, Melissa Kacena talked to her team.

I told them that not everyone has these kinds of opportunities to work with NASA, she said. I reminded them when I was a grad student, working with NASA really inspired me and opened doors. Hopefully they will solve the problems of tomorrow.

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Denver artist Kacena tapped by sister to design NASA patch for Rodent Research IV mission - The Denver Post