It's hard out there for a woman in STEM. In the male-dominated STEM fields, it can be difficult for a woman to break in, and once she does, it can be even harder for her to earn the respect and recognition of her colleagues. Luckily, we have occasions like Ada Lovelace Day on Oct. 14, 2014 to help celebrate the achievements of women in STEM.

Lovelace was a 19th-century countess and the daughter of famous poet Lord Byron who began learning mathematics from an early age. At the age of 17, Lovelace met mathematician Charles Babbage, and he showed her his plans for a machine that could do complex mathematical equations. Lovelace wrote about Babbage's plans in a scholarly journal and envisioned it to be used to show not just numbers but also words, pictures and music. She even illustrated how the machine could be used to calculate a set of Bernoulli Numbers using punch cards.

So in essence, Lovelace was the first computer programmer, male or female. Pretty cool, huh? Like Lovelace, there are plenty of other stories of women whose accomplishments in STEM changed the world, but that history seems to have forgotten. Here are five more women in STEM who should be household names.

Lise Meitner

Lise Meitner was an Austrian-born physicist who discovered that atomic nuclei split during some uranium reactions, giving birth to the concept of nuclear fission. This is a notable instance of a woman's contributions being overlooked in STEM. Meitner's colleague Otto Hahn, who had been performing the experiments, failed to name Meitner as a co-author when he published the chemical evidence for fission. In 1944, Hahn alone received the Nobel Prize.

Roberta Williams

Not many people know about Roberta Williams, but she is one of the most influential individuals in video game history. With her husband Ken, Williams founded the successful game developing company Sierra On-Line and created the first graphic adventure game, Mystery House. She would go on to create the King's Quest series, which sold millions of copies.

Jocelyn Bell Burnell

Jocelyn Bell Burnell wasn't even finished with grad school at Cambridge University before she made a major discovery. In 1967, Bell Burnell found what would come to be known as pulsars, fast-spinning, dense, collapsed stars. The discovery earned the 1974 Nobel Prize in Physics but not for Bell Burnell. Her supervisor Anthony Hewish and Martin Ryle, a fellow radio astronomer at Cambridge, received the award.

Maria Mitchell

Maria Mitchell also made great strides in astronomy. Mitchell discovered a comet, which came to be known as Miss Mitchell's Comet. She would go on to become the first woman elected to the Academy of Arts and Sciences in 1848.

Esther Lederberg

Eshter Lederberg made groundbreaking discoveries in how genes work, such as the lambda phage, a virus that infects E.coli bacteria. Unfortunately, this is another case of a woman in STEM not being recognized for her work as her first husband Joshua Lederberg won the Nobel Prize for Physiology or Medicine in 1958 for their work on how bacteria mate.